404 results about "Phosphorus doping" patented technology

The invention discloses a solar cell and a preparation method and application thereof, and relates to the technical field of solar cells. P-type doped regions and N-type doped regions are alternately arranged on the back surface of the crystalline silicon substrate, a boron diffusion doped layer, a first passivation layer and a first antireflection layer are sequentially arranged in the P-type doped regions, and a phosphorus-doped silicon oxide layer, a phosphorus-doped polycrystalline silicon layer, a second passivation layer and a second antireflection layer are sequentially arranged in the N-type doped regions from the surface of the crystalline silicon substrate. A traditional TBC battery P region mostly adopts a two-step process of intrinsic amorphous silicon deposition and boron diffusion to form a polycrystalline silicon layer, but the P region does not contain the polycrystalline silicon layer and can be prepared through a one-step boron diffusion process, so that the process steps can be reduced, and the process time can be shortened; and the action of laser and P-region polycrystalline silicon is avoided, the patterning difficulty of the battery is reduced, and the production yield of the battery can be greatly improved.

The invention relates to a crystal bar axial resistivity control method and device, and the method comprises the steps: predicting the first antimony evaporation capacity of a crystal pulling equal-diameter process in an antimony-phosphorus co-doped single crystal furnace according to the incidence relation between the evaporation constant in the antimony-phosphorus co-doped single crystal furnace and the excess material weight, and controlling the antimony-phosphorus doping ratio of the equal-diameter process according to the first antimony evaporation capacity; according to the incidence relation between the evaporation constant and the lead-discharge duration, the second antimony evaporation capacity in the crystal pulling lead-discharge process in the antimony-phosphorus co-doped single crystal furnace is predicted, and the antimony-phosphorus doping proportion in the lead-discharge process is controlled according to the second antimony evaporation capacity; and according to the target re-feeding evaporation calculation model, predicting a third antimony evaporation capacity in a re-feeding stage in the antimony-phosphorus co-doped single crystal furnace, and controlling an antimony-phosphorus doping ratio in the re-feeding stage according to the third antimony evaporation capacity, so that the axial resistivity uniformity of the crystal bar obtained by straight pulling is within a target range. At least the uniformity of axially doped elements in monocrystalline silicon can be improved in the crystal pulling process, and the uniformity of the axial resistivity of a crystal bar is improved.

The invention relates to the technical field of electrode materials, in particular to a silicon-carbon negative electrode material and a preparation method and application thereof. The silicon-carbon negative electrode material comprises a plurality of silicon-carbon composite particles, each silicon-carbon composite particle comprises porous carbon, nano silicon particles and phosphorus element which are attached in pores of the porous carbon, and coating carbon for coating the porous carbon, and n-type doping of the phosphorus element is formed at the joint of the nano silicon particles and the porous carbon. The preparation method comprises the following steps: (1) adsorbing phosphoric acid in porous carbon, and carrying out a heating reaction in a protective gas atmosphere to generate phosphorus-infiltrated porous carbon; (2) introducing a gaseous silicon source in a protective gas atmosphere, and carrying out silicon deposition on the phosphorus-infiltrated porous carbon by adopting a chemical vapor deposition method to obtain a phosphorus-doped silicon carbon material; and (3) carrying out carbon coating on the phosphorus-doped silicon carbon material to obtain the phosphorus-doped silicon carbon material. According to the method, the rate capability of the silicon-carbon negative electrode material can be remarkably improved while high first efficiency and high gram capacity are ensured.

The invention discloses a passivation contact cell with a selective polysilicon layer and a method of making the same. According to the invention, each laser scanning line on the back surface of the TOPCon solar cell adopts a separation form and is separated by the phosphorus heavily-doped polycrystalline silicon layer, so that overlapping of laser scanning paths does not exist, and a part of the phosphorus-doped polycrystalline silicon layer structure in the surrounding area of the main grid is reserved; according to the structure mode, the transmission distance of carriers in a laser ablation area can be reduced, the carriers can be collected by the fine grid more quickly, and the filling factor FF of the cell is improved especially under the special conditions of grid breakage and the like. According to the invention, the laser grooving area is 40%-80% of the total area of the back of the cell, which is beneficial for balancing the passivation performance of the cell while reducing the parasitic absorption of the polycrystalline silicon to light. The passivation contact cell has high short-circuit current, open-circuit voltage and fill factor.

The invention relates to the technical field of back contact solar cells, in particular to a back contact solar cell with a double-passivation structure and a preparation method thereof, and the front surface of the cell sequentially comprises an antireflection film, a suede structure and an N-type monocrystalline silicon wafer from outside to inside; a back field region on the back surface of the back contact solar cell sequentially comprises a metal electrode, an antireflection film, a second phosphorus-doped polycrystalline silicon layer, a second tunneling oxide layer, a first phosphorus-doped polycrystalline silicon layer, a first tunneling oxide layer and an N-type monocrystalline silicon wafer from outside to inside; the emitter region sequentially comprises a metal electrode, an antireflection film, a transparent conductive film, a boron-doped amorphous silicon layer, an intrinsic amorphous silicon layer and an N-type monocrystalline silicon wafer from outside to inside; the isolation area sequentially comprises an antireflection film, a suede structure and an N-type monocrystalline silicon wafer from outside to inside. A P-type TOPCon structure of an emitter region of the TBC battery is optimized into an intrinsic amorphous silicon + P-type amorphous silicon passivation structure with better passivation performance and contact performance, and the conversion efficiency is improved.

The invention belongs to the technical field of back contact photovoltaic cells, and particularly relates to a back contact photovoltaic cell with high-concentration co-doped regions and a manufacturing method and application thereof.The back contact photovoltaic cell with the high-concentration co-doped regions is characterized in that N-type doped regions and P-type doped regions which are alternately distributed are arranged on the backlight face of an intrinsic amorphous silicon layer, and the high-concentration co-doped regions are arranged between the N-type doped regions and the P-type doped regions; a doping source of the co-doped region comprises doping source phosphorus of the N-type doped region and doping source boron of the P-type doped region, the co-doped region, the doping source of the N-type doped region and the doping source of the P-type doped region form a specific concentration gradient structure, and the specific concentration gradient structure meets the condition that the doping concentration of phosphorus contained in the co-doped region is greater than that of phosphorus contained in the N-type doped region; the doping concentration of boron contained in the co-doped region is greater than the doping concentration of boron in the P-type doped region. The carrier transport and collection efficiency is optimized, the fill factor and open-circuit voltage are improved, the cell conversion efficiency and stability are improved, the preparation process is simple, and multiple times of opening etching are not needed.

The invention relates to the technical field of sensors, in particular to a high-sensitivity pressure-temperature dual-mode sensor and a preparation method thereof.The preparation method comprises the steps that a carbon nano tube is subjected to acid treatment and then reacts with a silane coupling agent KH550, and an aminated carbon nano tube is prepared; the method comprises the following steps: carrying out hydrothermal reaction on a phosphorus source and a graphene oxide aqueous solution to prepare phosphorus-doped reduced graphene oxide; the preparation method comprises the following steps: synthesizing Au-Ag heterojunction nano dispersion liquid through an Au nano seed method; mixing the three components and carrying out ultrasonic treatment to obtain mixed dispersion liquid; the preparation method comprises the following steps: modifying a PDMS substrate with KH560 and polyethylene glycol diamine to prepare a modified PDMS substrate; and coating the mixed dispersion liquid on a modified substrate to form a sensitive layer, and preparing an electrode to obtain the sensor. The aminated carbon nanotubes and the phosphorus-doped reduced graphene oxide construct a three-dimensional conductive network, so that high-sensitivity pressure detection is realized; the phosphorus-doped reduced graphene oxide and the Au-Ag heterojunction form a Schottky barrier, so that stable temperature sensing is realized; and the modified PDMS and the sensitive layer are strongly combined to improve the mechanical durability.

The present disclosure concerns a switching device comprising a first phosphorus-doped silicon layer on top of and in contact with a second arsenic-doped silicon layer. The present disclosure also concerns a method of making a switching device that includes forming a phosphorus-doped silicon layer in an arsenic-doped silicon layer.

The invention relates to the technical field of MOS (Metal Oxide Semiconductor), and discloses an MOSFET (Metal Oxide Semiconductor Field Effect Transistor) semiconductor structure for optimizing source and drain contact, which comprises a drain, a semiconductor epitaxial layer, a source and a grid, the semiconductor epitaxial layer comprises an N substrate layer, an N drift layer, a P well layer, an N well layer and a P-layer, the P-layer is internally provided with source polycrystalline silicon, and the N drift layer is internally provided with drain polycrystalline silicon. The top end of the source polycrystalline silicon is in ohmic contact with the source electrode; three metal oxide layers are arranged in the N well layer, and the top ends of the three metal oxide layers are connected with a source electrode; a plurality of semicircular metal layers are also arranged in the drain electrode; and the semicircular metal layers are in ohmic contact with the N substrate layer. According to the invention, a low-resistance channel is formed through the high-concentration phosphorus-doped heavily-doped gate, the charge and discharge time of gate charges is reduced, and the doped gate provides an additional conductive path, so that the switching time is reduced, the power conversion efficiency is improved, and the heat loss is reduced.

A preparation method for a solar cell includes: providing a silicon wafer having a first surface and a second surface opposite to the first surface; forming an ultrathin silicon oxide layer on the first surface of the silicon wafer, and sequentially forming a phosphorus-doped amorphous silicon layer and a silicon oxide mask layer on the ultrathin silicon oxide layer; and annealing the silicon wafer to densify the silicon oxide mask layer and convert the phosphorus-doped amorphous silicon layer into a phosphorus-doped polycrystalline silicon layer.

The invention relates to a preparation method of a local ITO interconnected perovskite-TOPCon laminated cell, which comprises the following steps: taking an n-type monocrystalline silicon wafer as a substrate, cleaning and texturing, diffusing boron on the back to form a P + emitter, oxidizing at high temperature, and treating the surface through acid etching and alkali polishing; sequentially preparing a tunneling oxide layer and a phosphorus-doped polycrystalline silicon layer on the front surface, annealing and crystallizing, depositing an aluminum oxide film and a multi-layer silicon nitride film on the back surface after cleaning, and depositing a single-layer silicon nitride film on the front surface; preparing a back metal electrode, etching according to a designed pattern to remove a local silicon nitride film on the front surface, sequentially preparing an ITO interconnection layer, a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer and an ITO transparent conductive layer on the front surface, and finally preparing a front metal electrode and solidifying to form a contact electrode. According to the invention, the problems of back corrosion risk, effective area loss and tedious process in the existing method are solved, full-size manufacturing is realized, the cell performance is improved, and industrialization is easier.

The invention provides a silicon-carbon negative electrode material and a preparation method thereof, a negative electrode and a lithium ion battery, and particularly relates to the technical field of negative electrode materials, the silicon-carbon negative electrode material comprises a porous carbon substrate, a silicon-containing substance and a phosphorosilicate glass coating layer, the silicon-containing substance is loaded in pore channels of the porous carbon substrate and forms a silicon-carbon compound, and the phosphorosilicate glass coating layer is coated with the silicon-carbon compound. The surface of the silicon-carbon compound is coated with the phosphorosilicate glass coating layer, phosphorus elements entering the silicon-carbon compound through thermal diffusion doping are arranged in the silicon-carbon compound, and a phosphorus-doped region is formed. The phosphorosilicate glass coating layer improves the strength of the silicon-carbon negative electrode and inhibits the volume expansion of the silicon-carbon negative electrode material. Meanwhile, the electrical property of the silicon-carbon negative electrode is improved through phosphorus doping, the structural stability and the electrochemical performance of the silicon-carbon negative electrode are improved, and the cycle life is prolonged.

The invention belongs to the technical field of photovoltaic cells, and particularly relates to a back contact photovoltaic cell, a back contact photovoltaic cell assembly and a preparation method, and the method comprises the steps: providing an N-type silicon wafer which is provided with a double-sided texturing structure, and the textured surface is of a pyramid structure after texturing; boron diffusion is carried out on the backlight surface of the silicon wafer to form a P + doping layer, and meanwhile, a lightly doped P-type region is formed on the illuminated surface of the silicon wafer through diffusion and dissipation; performing laser film opening on the backlight surface P + doping layer to form P region and N region structures which are distributed in a staggered manner; depositing a tunneling oxide layer and a phosphorus-doped amorphous silicon layer in the N region, and annealing the tunneling oxide layer and the phosphorus-doped amorphous silicon layer to form an N + polycrystalline silicon layer; printing etching slurry on the surface of the P region, performing etching slurry film opening, removing phosphorosilicate glass and forming an isolation gap between the P region and the N region; and the film is opened by printing etching slurry, so that the suede cannot generate thermal damage.

The invention provides a preparation method of a P-type solar cell and the P-type solar cell, and relates to the technical field of photovoltaics. The method comprises the following steps: providing a P-type silicon wafer, wherein a first surface of the P-type silicon wafer comprises a P-type region and an N-type region; a tunneling oxide layer, a phosphorus-doped polycrystalline silicon layer and a phosphorosilicate glass layer are sequentially stacked in the N-type region; the P-type region is exposed; the phosphorosilicate glass layer of the N-type region is used as a first mask layer, and the P-type region is polished, so that a polished structure is formed in the P-type region; forming a second mask layer on the phosphorosilicate glass layer and the polishing structure; and under the protection effect of the second mask layer, texturing the second surface of the P-type silicon wafer, so that a textured structure is formed on the second surface. The phosphorosilicate glass layer protects the N-type region, and the P-type region forms a polishing structure, so that better contact with electrode slurry in the later period is facilitated. The phosphorosilicate glass layer and the polishing structure are protected by the second mask layer, so that the adjusting range of the second surface texturing parameter is enlarged.

The invention provides phosphorus-doped coated asphalt and a preparation method thereof, a negative electrode material and a lithium battery. The preparation method of the phosphorus-doped coated asphalt comprises the following steps: mixing a phosphorus source and a first carbon source, and carrying out heat treatment to obtain the phosphorus-doped coated asphalt, the mass ratio of the first carbon source to the phosphorus source is 20: (1-4), and the heat treatment temperature is 100-400 DEG C. The invention also provides a negative electrode material and a lithium battery prepared on the basis of the phosphorus-doped coated asphalt. The coating layer on the surface of the graphite is modified, and phosphorus is introduced into the amorphous carbon coating layer, so that lithium storage sites of the graphite negative electrode material can be increased, and the specific capacity of the material is improved; meanwhile, the structure of the coating layer can be improved, the short-range ordered structure of the doped coating layer is increased, the interlayer spacing is enlarged, and the rate capability of the graphite negative electrode material is improved.

The invention provides a doped lithium-rich manganese-based precursor, a preparation method thereof, a positive electrode material and a battery, and relates to the technical field of preparation of battery positive electrode materials. Fluorine and phosphorus doped elements are synchronously added in the precursor synthesis process and can be uniformly dispersed in the precursor, the nucleation and growth modes of the precursor are induced by utilizing the adsorption characteristics and the synergistic induction effect of the fluorine and phosphorus elements, and the precursor morphology with needle-shaped radial arrangement is synthesized. The lithium-rich material with the corresponding morphology is beneficial to migration and transmission of lithium ions from the inside to the outside of the material on one hand, meanwhile, the stress is small, and the structure is more stable in the circulation process.

The invention provides a method for improving passivation contact performance of a p region of a TBC battery, which comprises the following steps of: pretreating an n-type monocrystalline silicon wafer, depositing a SiO2 layer and boron (B) doped polycrystalline silicon (poly-Si), etching, performing laser ablation and the like, then depositing phosphorus (P) doped poly-Si, and finally depositing a passivation and anti-reflection layer and preparing a metal electrode. A tunneling oxide layer and boron in-situ doped polycrystalline silicon are deposited in a p region by adopting an ultra-low temperature plasma enhanced chemical deposition (PECVD) mode, the reaction of SiH4 and N2O is introduced to improve the deposition effect of the oxide layer at low temperature, the compactness of a film layer at low temperature is ensured to improve the separation of B on a SiO2 / c-Si interface, and the passivation performance is improved; b doping poly-Si is adopted in the p region, meanwhile, processing is matched with a nanosecond laser, non-equilibrium doping of the B to the poly-Si is achieved, the ultrahigh doping concentration is obtained, the p region passivation performance of the TBC is improved, and then the open-circuit voltage and the conversion efficiency of the TBC battery are finally improved.

The invention discloses a passivation method of a boron and phosphorus doped Poly layer, a passivation contact structure of the boron and phosphorus doped Poly layer and a battery. The passivation method comprises the following steps: firstly, growing a tunneling oxide layer with two thin and compact sides and a thick and loose middle on the surface of a silicon wafer by adopting a mode of combining low-temperature low-pressure oxidation, high-temperature normal-pressure oxidation and low-temperature normal-pressure oxidation, and then carrying out deposition and oxidation propulsion of boron atoms and / or phosphorus atoms by adopting a high-temperature diffusion tube, so that boron and phosphorus with a certain concentration are doped in a Poly silicon layer. According to the invention, through superposition of the oxide layers with different compactness, the overall thickness of the tunneling oxide layer is improved, so that the structure of the tunneling oxide layer is not obviously damaged in the subsequent boron and phosphorus diffusion process, and the passivation effect of the boron and phosphorus doped Poly layer is obviously improved. According to the passivation method disclosed by the invention, Poly silicon layers and doped polycrystalline silicon layers with different thicknesses can be obtained, and the passivation method can be applied to all batteries needing to use boron Poly and phosphorus Poly.

The present invention provides a multi-layer doping source structure, and a high-quality emitter and a controllable preparation method therefor. The multi-layer doping source structure comprises a dielectric layer, a nitrogen silicide layer and a doping source layer, which are stacked on the front surface of a crystalline silicon substrate, wherein the dielectric layer is a silicon oxide film or a silicon oxynitride film, the doping source layer is boron-doped amorphous silicon doped with functional elements or phosphorus-doped amorphous silicon doped with functional elements, and the functional elements doped in the doping source layer are carbon and / or nitrogen. In the present invention, the doping source structure is composed of the dielectric layer, a nitrogen silicide and boron- / phosphorus-doped amorphous silicon doped with functional elements; the multi-layer doping source structure has both a strong laser absorption capability and a high boron or phosphorus doping concentration, thereby facilitating a reduction in the laser power and the illumination time required by a laser selective emitter technique; moreover, such a multi-layer doping source structure is favorable for reducing the surface boron concentration, decreasing defects and improving the passivation effect of an emitter, and therefore an improvement in battery efficiency can be promoted.

A solar cell and a preparation method thereof belong to the field of photovoltaic technology, the solar cell at least comprises a substrate, a tunneling oxide layer, a tin oxide layer and a doped polycrystalline silicon layer, along the thickness direction of the substrate, the tunneling oxide layer is arranged on the surface of the substrate, the tin oxide layer is arranged on the surface of the tunneling oxide layer, and the doped polycrystalline silicon layer is arranged on the surface of the substrate. The doped polycrystalline silicon layer is arranged on the surface of the tin oxide layer, so that the tin oxide layer is located between the tunneling oxide layer and the doped polycrystalline silicon layer. The phosphorus doping concentration alpha of the tunneling oxide layer satisfies 1 * 10 < 13 > cm <-3 > < = alpha < = 1 * 10 < 16 > cm <-3 >, the phosphorus doping concentration beta of the tin oxide layer satisfies 1 * 10 < 15 > cm <-3 > < = beta < = 1 * 10 < 20 > cm <-3 >, and the phosphorus doping concentration gamma of the doped polycrystalline silicon layer satisfies 1 * 10 < 19 > cm <-3 > < = gamma < = 1 * 10 < 21 > cm <-3 >. The tin oxide layer is arranged between the tunneling oxide layer and the doped polycrystalline silicon layer, the tin oxide layer has excellent conductivity and light transmission, parasitic absorption is reduced, more light is absorbed by the substrate, and the photoelectric conversion efficiency of the solar cell is improved.

The utility model provides a TOPCon cell sheet capable of reducing back parasitic absorption and a photovoltaic assembly, and relates to the technical field of solar cells. The TOPCon battery piece capable of reducing parasitic absorption on the back surface comprises an N-type crystalline silicon substrate, wherein a first tunneling oxide layer, an intrinsic polycrystalline silicon layer, a second tunneling oxide layer, a phosphorus-doped polycrystalline silicon layer, a third tunneling oxide layer and a transparent conductive film sequentially cover the back surface of the N-type crystalline silicon substrate. The TOPCon battery piece comprises the N-type crystalline silicon substrate, so that on the basis of reducing the thickness of the Poly-Si composite layer on the back surface, parasitic absorption is reduced, the light utilization rate is increased, and composite current and contact resistance are reduced, so that the efficiency of the battery piece is effectively improved.

The invention provides a positive electrode precursor, a preparation method of the positive electrode precursor, a positive electrode material and a preparation process of the positive electrode material. The positive electrode precursor comprises a phosphorus-doped seed crystal, a phosphorus-doped layer coated outside the phosphorus-doped seed crystal, and a zirconium-rich shell layer coated outside the phosphorus-doped layer, and the mass fraction of doped phosphorus in the phosphorus-doped seed crystal is greater than the mass fraction of doped phosphorus in the phosphorus-doped layer. In the positive electrode precursor provided by the invention, due to introduction of gradient concentration doping of phosphorus, separation of lattice oxygen and mixed arrangement of cations are inhibited, the structural stability of the positive electrode material is enhanced, and the risk that the positive electrode material generates microcracks in the circulation process is reduced; in addition, due to the coating of the zirconium-rich shell layer, not only is the residual alkali reduced, but also the corrosion resistance and the stability of the positive electrode precursor are improved; therefore, the battery prepared from the positive electrode precursor provided by the invention shows relatively high first charge-discharge efficiency and rate capability and excellent cycle stability.

The invention discloses a preparation method of phosphorus-doped and closed-pore synergistically regulated biomass hard carbon and application of the phosphorus-doped and closed-pore synergistically regulated biomass hard carbon in a negative electrode of a sodium-ion battery, and belongs to the technical field of electrode materials. The preparation method comprises the following steps: preparing a water-based starch suspension with a certain mass fraction by taking starch as a biomass precursor, carrying out a cross-linking reaction through sodium trimetaphosphate to form a phosphate ester bond bridged stable network structure, pre-oxidizing the cross-linked precursor, and then carbonizing in a high-temperature inert atmosphere to obtain the water-based starch composite material. And the hard carbon material with expanded interlayer spacing, phosphorus doping and high closed pore volume is prepared. The material shows high reversible capacity, high initial coulombic efficiency, excellent rate capability and cycling stability when being used as a sodium-ion battery negative electrode active material. According to the preparation method disclosed by the invention, through a simple cross-linking-carbonizing process, cooperative regulation and control of heteroatom doping and a closed-pore structure are realized, and a new strategy is provided for large-scale preparation of the high-performance biomass hard carbon negative electrode.

The embodiment of the invention relates to the field of photovoltaic technology, and provides a solar cell and a preparation method thereof, and a solar cell production line. The preparation method of the solar cell comprises the following steps: forming a first lamination layer comprising a first tunneling layer, a boron-doped polycrystalline silicon layer and a first mask layer on a first surface of an N-type silicon substrate; corresponding parts of the first lamination layer and the N-type silicon substrate in the second region and at least part of the spacer region are removed, so that a groove is formed in the N-type silicon substrate, and the groove surface, formed in the N-type silicon substrate, of the groove is arc-shaped; forming a second lamination layer comprising a second tunneling layer, a phosphorus-doped polycrystalline silicon layer and a second mask layer which are laminated in sequence on the whole side of the first surface; the winding plating layer is removed, the winding plating layer is wound and plated on the second surface of the N-type silicon substrate when the first lamination layer and / or the second lamination layer are / is formed, and the second surface is opposite to the first surface; removing corresponding parts of the second lamination layer in the first region and the spacer region; and removing the first mask layer and the second mask layer.

The present disclosure relates to the technical field of solar cells. Disclosed are a solar cell, a preparation method therefor and a use thereof. A P-type doped region and an N-type doped region are alternately arranged on the back surface of a crystalline silicon substrate; a boron diffusion doped layer, a first passivation layer and a first anti-reflection layer are sequentially formed in the P-type doped region; and a phosphorus-doped silicon oxide layer, a phosphorus-doped polycrystalline silicon layer, a second passivation layer and a second anti-reflection layer are sequentially formed on the surface of the crystalline silicon substrate in the N-type doped region. The P regions of traditional TBC cells mostly adopt a two-step process of depositing intrinsic amorphous silicon and performing boron diffusion to form a polycrystalline silicon layer. However, the P region of the present disclosure does not contain a polycrystalline silicon layer, and can be prepared by a one-step boron diffusion process, which can reduce the process steps and shorten the process time. The interaction between laser and the polycrystalline silicon in the P region is also avoided, the difficulty of cell patterning is reduced, and the production yield of cells can be greatly improved.

The invention provides a solar cell, a preparation method thereof and a photovoltaic module. The solar cell includes: a substrate; the first tunneling oxide layer is located on the surface of one side of the substrate; the first phosphorus doped layer is located on the surface of one side, far away from the substrate, of the first tunneling oxide layer; the second tunneling oxide layer is located on the surface of the side, away from the first tunneling oxide layer, of the first phosphorus-doped layer; the second phosphorus-doped layer is located on the surface of one side, far away from the first phosphorus-doped layer, of the second tunneling oxide layer; the third tunneling oxide layer is located on the surface of the side, away from the second tunneling oxide layer, of the second phosphorus-doped layer. The third phosphorus-doped layer is located on the surface of one side, far away from the second phosphorus-doped layer, of the third tunneling oxide layer; wherein the doping concentration of phosphorus in the first phosphorus-doped layer is smaller than the doping concentration of phosphorus in the second phosphorus-doped layer, and the doping concentration of phosphorus in the second phosphorus-doped layer is smaller than the doping concentration of phosphorus in the third phosphorus-doped layer. The solar cell has a good passivation effect.

The invention discloses a preparation method of a TOPCon solar cell. The preparation method comprises the following steps: S1, polishing the back surface of a silicon wafer; s2, depositing a tunneling oxide layer, a phosphorus-doped amorphous silicon layer and a mask layer on the back surface; s3, performing alkali texturing on the front surface; s4, depositing a tunneling oxide layer and an intrinsic amorphous silicon layer on the front side; s5, performing boron diffusion on the front surface, and synchronously crystallizing the phosphorus-doped amorphous silicon layer on the back surface to form a phosphorus-containing polycrystalline silicon layer; s6, carrying out laser crystallization; s7, removing the surface layer parts of the side surface BSG layer and the back surface mask layer; s8, removing the side boron diffusion layer, the front BSG layer and the residual mask layer; s9, double-sided film coating; and S10, carrying out silk-screen printing, sintering and light injection. According to the method, single-side texturing of the silicon wafer can be realized, and excessive internal expansion of phosphorus atoms caused by too high crystallization temperature can be avoided by matching low-temperature boron diffusion with laser crystallization. According to the method, the thickness of the silicon wafer is reduced slightly, the fragmentation rate of the silicon wafer in the preparation process is reduced, and the optical performance of the cell can be further improved.

The invention discloses a preparation method of a Fe3O4 modified phosphorus-doped carbon-based porous wave-absorbing material constructed on the basis of a multi-component strategy. The preparation method comprises the following steps: firstly, preparing a phosphorus-doped carbon-based porous nano material through a freeze-drying method and a sacrificial template method, then obtaining a Fe3O4 intermediate through oil bath, and finally reducing for 6 hours in an Ar atmosphere to obtain the Fe3O4-modified phosphorus-doped carbon-based porous wave-absorbing material, namely Fe3O4 (at) P-NCP. Based on a good magnetic loss mechanism of the material, a synergistic effect of dielectric loss and magnetic loss is provided for electromagnetic wave absorption. And meanwhile, the porous structure ensures that incident electromagnetic waves can form multiple reflections in the porous structure. The material has the advantages of good microwave absorption performance, thin matching thickness, wide effective absorption frequency band and the like. A good foundation is provided for development of porous materials, and a good design thought is provided for preparation of electromagnetic wave absorbing materials. The good microwave absorption performance of the material can play a good role in electromagnetic radiation and pollution, and the material has a wide application prospect.

The invention provides a phosphorus-nickel co-doped carbon nitride composite material for photocatalytic-Fenton degradation of pollutants and a preparation method and application thereof, and the preparation method comprises the following steps: in a muffle furnace, heating urea and ammonium dihydrogen phosphate to convert into phosphorus-doped carbon nitride; the preparation method comprises the following steps: dissolving phosphorus-doped carbon nitride in absolute ethyl alcohol, adding an anhydrous nickel chloride aqueous solution, carrying out ultrasonic treatment, drying, placing in a muffle furnace, and carrying out high-temperature heating conversion to obtain the phosphorus-nickel co-doped carbon nitride composite material. According to the metal monatomic catalyst synthesized by adopting a specific preparation method, the yield of photo-generated hydrogen peroxide is selectively improved while separation and transfer of photo-generated carriers are synergistically promoted by two sites; and the iron circulation can be well promoted, so that the photocatalytic-Fenton pollutant degradation effect which is comparable with that of precious metal doping is realized.

The present invention relates to the field of photocatalysis, and provides a phosphorus-doped titanium dioxide and a preparation method thereof. The method for preparing the phosphorus-doped titanium dioxide comprises the following steps: S1: depositing titanium dioxide on black phosphorus nanosheets by a sol-gel method to obtain a black phosphorus / titanium dioxide composite material. S2: depositing silicon dioxide on the black phosphorus / titanium dioxide composite material prepared in S1 to obtain a black phosphorus / titanium dioxide / silicon dioxide composite material. S3: calcining and etching the black phosphorus / titanium dioxide / silicon dioxide composite material obtained in S2. The phosphorus-doped titanium dioxide prepared by the method provided by the present invention further improves the photocatalytic performance of titanium dioxide by preparing a titanium dioxide nanomaterial having the characteristics of large specific surface area, high uniformity of particle size, adjustable crystallinity and controllable crystal phase.